Gripping device

ABSTRACT

A gripping device is provided, generally in the form of two or more opposed fixtures, each having gripping teeth therein, for engaging an article to be gripped and pulled, wherein means are provided for assuring long life of the gripping fixtures.

[56] References Cited UNITED STATES PATENTS 1,487,440 3/1924 Butts............

Harry 1-. Roy

Norristown, Pa. 789,498

2,890,513 6/1959 Lane....

3,052,943 9/1962 Jones...........................

FOREIGN PATENTS 3/1961 GreatBritain................

[2 l Appl. N o.

[22] Filed Jan. 7,1969

[45] Patented Apr. 27, 1971 73] Assignee Luster-Jordan Manufacturing Co. Norristown, Pa.

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ABSTRACT: A gripping device is provided, generally in the form of two or more opposed fixtures, each having gripping to be gripped and pulled,

294/102, 294/106 51 ...A44b21/00 so teeth therein, for engaging an article wherein means are provided for gripping fixtures.

assuring long life of the PATENTED APR 27 m7:

IN VENTOR.

Hurry F. Hoy MM ATTORNEYS.

cnnrnsc navicn BACKGROUND OF THE INVENTION In the past, gripping devices have been used for various purposes, such as by using two or more to engage a mandrel on opposite sides of the mandrel for the purpose of pulling the mandrel from a wound roll of sheet plastic or the like, after winding the same, in order that the mandrel may be again used for the winding of additional rolls of sheet plastic thereon.

It is to be understood that, when winding sheet plastic or the like onto a mandrel, with the increased weight of the roll of sheet plastic the mandrel becomes more securely frictionally adhered to the inner bore of the roll to the extent that it becomes necessary to supply substantial axial forces capable of removing the mandrel from the roll. In this regard, it is commonplace to maintain the roll in position, and to grip the mandrel on opposite sides by means of gripping devices.

Gripping devices of the prior art have generally used pairs of opposed fixtures, which has serrated or toothed surfaces, the teeth in each surface being integral with an associated fixture, and being ground therein to a predetermined depth, sufiicicnt to permit a tight grip upon the item to be engaged. At least the toothed portions of such fixtures were hardened to a suitable hardness, sufficient to permit engaging and gripping against metal surfaces and the like, without unduly marring or scarring teeth of the gripping fixtures, in order to permit many uses of the gripping fixtures without requiring recutting and rehardening of the same.

As the teeth or toothed portions of each gripping fixture became worn, requiring repeated regrinding and rehardening, the fixtures eventually became reduced in size until it was necessary to replace the fixtures themselves, resulting in increased expense. Furthermore, each regrinding and rehardening operation performed on the toothed portions of the fixtures was in itself, a relatively expensive operation.

SUMMARY OF THE INVENTION The present invention is directed toward providing gripping fixtures, each of which is adapted for mounting in a conventional fixture holder, but wherein each fixture utilizes replaceable and repositionable gripping elements, the elements being constructed of sufficiently hardened steel to perform their gripping function, and wherein, each element is capable of presenting a plurality of gripping edges to the item to be gripped, and which may be selectively repositioned to place a desired edge into gripping engagement.

Accordingly, it is a primary object of this invention to provide a novel fixture wherein one or a plurality of repositionable elements may be secured therein, each element capable of presenting more than one gripping edge, upon selected repositioning of the same.

it is a further object of this invention to provide a novel gripping fixture, containing a plurality of repositionable gripping elements, which are mutually supportable within the fixture.

It is a further object of this invention to provide a novel gripping device, wherein two or more fixtures are utilized, each having a plurality of removable, replaceable, and repositionable gripping elements therein, each element having a plurality of gripping edges, and adapted for selected positioning within an asociated fixture for engagement against an item to be gripped.

It is a further object of this invention to accomplish the object immediately above, wherein the elements are clamped within their fixtures.

Other objects and advantages of the present invention will become readily apparent to one skilled in the art, from a reading of the following brief description of the drawing FIGS, detailed description of the preferred embodiment, and the appended claims.

it will be understood, that although the gripping devices of this invention are discussed herein for use in withdrawing mandrels from rolls of sheet plastic and the like, this represents only a singular example of a use for such gripping devices, although a wide variety of uses are contemplated. Other examples of such uses reside in wire drawing, steel drawing generally, and any other operation normally using gripping members to do a gripping and or pushing operation. It is also contemplated that the gripping devices of this invention could be used in conjunction with a gripping and pushing operation, and the disclosure herein is to be read accordingly.

IN THE DRAWINGS FIG. 1 is a fragmentary top plan view, with portions broken away and illustrated in section, of a pair of gripping devices of this invention, engaged within a clamp or holder, wherein the gripping elements of the devices are in clamping engagement against a mandrel of a large roll of sheet plastic, for pulling the mandrel from the roll, and wherein the roll is illustrated in engagement within a fixture to prevent axial movement of the roll during the pulling operation.

FIG. 2 is a perspective view of a gripping device of this invention, with its gripping elements contained therein, in locked engagement.

FIG. 3 is a perspective view of one of the gripping elements of this invention.

FIG. 4 is a side elevational view, with a portion illustrated in section, of a modified form of a gripping device of this invention.

Referring now to the drawing in detail, reference is made to FIG. 1, wherein there is fragmentally illustrated a large roll of sheet plastic or the like 10, wrapped about a cardboard sleeve 11 or the like, which in turn is disposed on a steel mandrel 12. Such a roll 10 is usually of relatively large weight, and it is thus desirable for minimizing shipping costs to remove the mandrel 12 therefrom prior to shipping the roll 10 to a user.

The roll 10 is supported against axial or endwise movement by placing the same within a bracket 13, with a circumferential portion of the roll 10 seated in an adjacent portion 14 of the bracket 13, and with the end of the roll 10 in an engagement against a transversely disposed leg 15 of the bracket 13, to secure the roll 10 against axial movement during the pulling operation.

A pair of gripping devices 16 and 17 are provided, each wedged against an associated wedge block 18 or 20, with each wedge block 18 and 20 being welded or otherwise secured to a U-shaped frame member 21, which in turn has an eye bolt 22 secured thereto, in which may be engaged a chain, rope, or like pulling device 23. g

The gripping devices 16 and 17 are identical in construction, and are thus each adapted to be moved together, toward one another, into gripping engagement against the periphery of the mandrel 12, by means of the inward component of force exerted against the outer surfaces 24 and 25 of the gripping devices 16 and 17, respectively, due to their engagement by the sloped surfaces 26 and 27 of the wedge blocks l8'and 20, respectively. In addition to this transverse component of force, directing the wedging devices into gripping engagements with the mandrel 12, an axial component of force is provided by means of the rope, chain or the like 23, pulling the U-member 21 in the direction of the arrow at the extreme left of FIG. 1, to exert a leftward directed endwise component of force through the gripping elements 16 and 17, onto mandrel 12.

With particular reference to FIG. 2, there is illustrated one of the gripping devices 17 which includes a fixture 30, having the sloped surface 25 mentioned above, and having a recess 31 therein which is defined by a base surface 32, a backwardly sloped surface 33, and a sloped surface 34 of a'wedge block 35, with the surfaces 33 and 34 being disposed in substantially parallel relation to one another, and at an acute angle with the axis of the mandrel 12, for example, of 45.

The wedge block 35 has a rear surface 36 which is also sloped at an angle of approximately with the base surface 32, to facilitate sliding of the wedge member 35 along the surface 32 of the fixture 17, for purposes of clamping a plurality of elements 37 therein, in a mutually supporting relation within the recess 31 of the fixture 17, between the surfaces 33 and 34 of the fixture 30.

In the embodiment illustrated, four elements 37 are disclosed, each being of rectangular cross section and having a length substantially greater than its width, such that each element 37 is adapted to present any of four gripping edges 38, 40, 41, or 42, to the mandrel 12, depending upon the selected position of that element 37 within the fixture 30. It will be apparent, that the elements 37 are each of hard construction, such as carbide steel or the like, for performing their gripping functions and that each element 37 is capable of being repositioned to present a new edge 38, 40, 41, or 42, as desired, or as each previously presented edge becomes worn or otherwise damaged. Furthermore, as a given element 37 becomes worn to the extent that all of its edges 38, 40, 41, and 42 are worn or damaged, a new element 37 may be provided and substituted therefore, each with four new edges, at a minimum of expense and substitution difficulty.

A wedge block 43 is provided, to be disposed between the rear surface 36 of the block 35 and a sloped surface 44 of the fixture 30, with block 43 having a pair of drilled and counterbored holes 45 and 46 therein, in which are received cap-headed screws 47 and 48 or like fastening members, these screws 47 and 48 being engaged within tapped holes or the like in the fixture 30, for tightening the member 43 onto the fixture 30, such that the clamp block 35 becomes longitudinally driven in the direction of the sloped surface 33, to securely wedge the element 37 within the recess 31.

It will further be apparent that the elements 37 may be replaced with a minimum of difficulty, such as by loosening the screws 47 and 48, in order to release an element 37 therefrom.

With reference to FIG. 4, one modified form of a gripping device 50 is illustrated, comprising a fixture 51 having a recess 52 therein. A plurality of unhardened holding blocks 52, 53, and 54 are slideably received within the recess 52. The blocks 52, 53, and 54 have notched surfaces 55, 56, 57 and 58 for receiving comers of hardened blocks 60, 61 of rectangular cross-sectional configuration. The blocks 60 and 61 are also adapted for repositioning and replacement as above described. The blocks 52, 53, 54, 60 and 61 are held in place by one or more set screws 62 in threaded engagement within the fixture 51.

it will be apparent from the forgoing, that various modifications may be made in the details of construction, of the gripping devices 16 and 17 of this invention, and also in the fixtures and clamping arrangements for holding such devices. For example, any such clamping arrangement for holding the devices 16 and 17 may be used, as long as it is capable of securing the gripping devices 16 and 17 against an item to be gripped, by exerting transverse forces thereagainst, and additionally exerting pulling or pushing forces thereagainst. Furthermore, the gripping device of this invention may also be used in conjunction with pressure application. The gripping elements 37 of this invention may be adapted for gripping flat surfaces, wire being drawn, rod stock or the like in addition to the circumferential or rounded surfaces provided by a mandrel 12. Still further, the gripping elements 37 of this invention need not be rectangular in cross section, but could be of any shape which permits ready repositioning of the element 37 to present a new gripping edge against an item to be gripped. For example, it is conceivable that gripping elements 37 of triangular cross section could be used, with only slight modifications of the clamp member 35. Other modifications will be apparent to those skilled in this art, within the scope of this invention, as defined in the appended claims.

lclaim:

l. A gripping device for use in exerting gripping and pulling forces comprising a pair of opposed fixture base members each having means for receiving gripping elements at predetermined gripping orientation therein, at least a pair of gripping elements, at least one said gripping element disposed in and securely carried by each said fixture base member at a predetermined orientation, means carried by each said fixture base member for clamping said gripping elements in said orientation, each said gripping element having a plurality of gripping edges numbering in excess of two, and being selectively repositionable within said member for presenting a corresponding selected gripping edge to an item to be gripped and means carrying said fixture members for securing said base members with their gripping elements in engagement with an article to be gripped.

2. The device of claim 1, wherein each said element is of flat, platelike construction, having four gripping edges thereon and wherein a plurality of said elements are clamped in each said fixture base member.

3. The device of claim 2, wherein the gripping edges of said elements in each fixture base member collectively define a gripping surface, and wherein each said element is disposed at an acute angle to the gripping surface.

4. The device of claim 1, wherein said fixture base member is of one-piece unitary construction and each said element receiving means comprises a recess, one end of said recess terminating in an undercut sloped surface as a part of said one-piece construction, and wherein said clamping means comprises a slide member disposed within said recess and movable toward said undercut sloped surface, for clamping engagement with associated said gripping element therebetween, and including means for locking said slide member in an element clamping position.

5. The device of claim 4, wherein said locking means include camming means for tightening said gripping elements in clamped engagement.

6. A gripping fixture for use in exerting gripping forces against an item to be gripped, comprising a base member, means for receiving at least one gripping element therein at predetermined gripping orientation, at least one gripping element, said gripping element having a plurality of gripping edges numbering in excess of two and being selectively repositionable within said member for presenting a corresponding selected gripping edge to an item to be gripped and means for clamping said element in said receiving means.

7. The fixture of claim 6, wherein a plurality of elements are provided in said receiving means, said elements being clamped therein in mutually supporting relation.

8. The fixture of claim 7, wherein each said element is of flat, platelike construction for presenting four gripping edges.

9. The fixture of claim 8, wherein each said element is of hardened construction.

10. The fixture of claim 6, wherein a plurality of holding elements are disposed in clamped relation within said receiving means, with notch means on said holding elements for receiving edges of gripping elements therein. 

1. A gripping device for use in exerting gripping and pulling forces comprising a pair of opposed fixture base members each having means for receiving gripping elements at predetermined gripping orientation therein, at least a pair of gripping elements, at least one said gripping element disposed in and securely carried by each said fixture base member at a predetermined orientation, means carried by each said fixture base member for clamping said gripping elements in said orientation, each said gripping element having a plurality of gripping edges numbering in excess of two, and being selectively repositionable within said member for presenting a corresponding selected gripping edge to an item to be gripped and means carrying said fixture members for securing said base members with their gripping elements in engagement with an article to be gripped.
 2. The device of claim 1, wherein each said element is of flat, platelike construction, having four gripping edges thereon and wherein a plurality of said elements are clamped in each said fixture base member.
 3. The device of claim 2, wherein the gripping edges of said elements in each fixture base member collectively define a gripping surface, and wherein each said element is disposed at an acute angle to the gripping surface.
 4. The device of claim 1, wherein said fixture base member is of one-piece unitary construction and each said element receiving means comprises a recess, one end of said recess terminating in an undercut sloped surface as a part of said one-piece construction, and wherein said clamping means comprises a slide member disposed within said recess and movable toward said undercut sloped surface, for clamping engagement with associated said gripping element therebetween, and including means for locking said slide member in an element clamping position.
 5. The device of claim 4, wherein said locking means include camming means for tightening said gripping elements in clamped engagement.
 6. A gripping fixture for use in exerting gripping forces against an item to be gripped, comprising a base member, means for receiving at least one gripping element therein at predetermined gripping orientation, at least one gripping element, said gripping element having a plurality of gripping edges numbering in excess of two and being selectively repositionable within said member for presenting a corresponding selected gripping edge to an item to be gripped and means for clamping said element in said receiving means.
 7. The fixture of claim 6, wherein a plurality of elements are provided in said receiving means, said elements being clamped therein in mutually supporting relation.
 8. The fixture of claim 7, wherein each said element is of flat, platelike construction for presenting four gripping edges.
 9. The fixture of claim 8, wherein each said element is of hardened construction.
 10. The fixture of claim 6, wherein a plurality of holding elements are disposed in clamped relation within said receiving means, with notch means on said holding elements for receiving edges of gripping elements therein. 